Improvement in steam-boilers



UNITED STATES PATENT OFFTCE.

JAMES MURPHY, OF NEW YORK, N. VY.

IMPROVEMENT IN STEAM-BOILERS.

Speciiication forming part of Letters Patent No. 13,223, dated July 10, 1855.

To all whom, it may concern:

Be it known that I, JAMES MURPHY, of the city, county, and State of New York, have invented certain new and useful Improvements in Tubular Steam-Boilers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a longitudinal vertical section of a boiler` on my improved plan; Fig. 2, a horizontal section taken at the line A a of Fig. l; Fig. 3, a cross vertical section taken at the line B b of Fig. l; and Figs. 4t, 5, and 6, sections of a tube and part of the tube-sheets on an enlarged scale.

The same letters indicate like parts in all the figures.

In that class of tubular steamsboilers in which the water circulates through the tubes and the heated products of combustion outside the use of cylindrical or oval tubes is attended with seriousinconveniences. In the first place the amountof surface exposed to the direct action of the flame and other heated products of combustion is proportionally small, for the reason that the products of combustion traveling in one direction can only impinge on that half of the circumference of the tubes facing the current, while 4the other half is only heated by radiation. In the second place it is very dili'icult to remove the iucrustation from the inside of cylindrical or oval tubes, for the reason that the scale presents an arched form, which resists with great tenacity the action of .the tool, and in consequence the tubes are often so seriously injured as to yield to the pressure and burst, and with cylindrical tubes of small diameter it is extremely diiicult to introduce suitable instruments for removing the scale; and in the third place it has been found extremely difiicult to secure oval tubes to the tube-sheet on account of the supposed necessity of employing flan ges on the ends of the tubes to effect the union, it being well known that when iianges are used the tubes cannot be placed sufciently near to each other to obtain the required amount of lire-surface within a small compass, and although the use of oval or elliptical or flattened cylindrical tubes has been suggested as substitutes for cylindrical tubes the difficulty of securing them to the tube-sheets and their liability to be crushed or collapsed or forced outward on the tlat sides must have prevented the introduction of them into practical use, notwithstanding the many advantages which they present in other respects.

The object of my invention is to secure tubes of such form to the tube-sheets, so as to prevent the pressure from loosening the joints; and to this end my invention consists in grooving the surface of the tubesheets wholly or partly around the holes to receive the edges of the metal of the tubes when turned over and riveted, which effectually holds the flat sides of the tubes and makes tight and strong joints not liable to leak.' In the accom pauyin g drawings, a represents the place for the furnace, and l) a horizontal liuc-space containing a series of vertical water-tubes c, secured at bottom and top to the tube-sheets d c. The lower ends of the tubes communicate with the bottom water-chamber f and their upper ends with a water-space g. The rear end of the flue-space b communicates by a vertical ilue h with another horizont-al or return flue z above, which leads to the chimney j, and in this Ilue 'L' are also arranged other tlat Vertical water-tubes c, which communicate with the water-space g and with the chamber 7o above.

The drawings represen t a double boiler with two furnaces, and as both are alike only one of them will be described. The water-spaces and chamber above are all connected by wate`r-spaces Z Z and m m at the sides and ends, that the water may rise in the tubes and descend in the water-spaces Z l and m m, thus keeping up a circulation in manner well known. The flat tubes are arranged with the fiat sides parallel and in the direction ot' the length of the ilues and in series of rows, the second row being opposite the spaces between the tubes of the first row, and so with any number of rows, so that the products of combustion after passing the tubes of the first row shall impinge against the semicylindrical front surface of the second row, and so with the series of rows in succession. They may, however, if desired, be differently arranged with reference to the line of passage of the current of the products of combustion.

The tubes c are, as represented, flat with the sides parallel and the front and back connecting the sides semi-cylindrical. The tubes are beaded, as at 1ML, and so near to each end as to leave the required length beyond the beads to pass through the tube-sheets and to be riveted. The tubes pass through holes of corresponding size in the tube-sheets, and the beads rest against the inner surface of the tube-sheets, in the manner of a flange 0r eollar, and the tubes are riveted over the surface of the tube-sheets.

The surface of the tube-sheets is grooved, as at o, around or partly around the holes through which the tubes pass, so that when the ends of the tubes are bent over in riveting the metal will be forced into the grooves andv thus effectnally bind the tubes to the tube-sheets in all directions. i lf desired, the grooves may be dispensed with around the curved portions of the tubes, as the principal object is to hold the flat portion, which from the form would be likely to be bent or collapsed; but being thus held by the lapping of the end of the tubes into the `grooves in i riveting good permanentrjoints are secured. Stay-bolts, as at p, are to be insertedaeross the tubes to brace the two at and therefore weakest portions of the tubes. In this Way, by the use of the beads acting as shoulders or flanges and the riveting or bending over the ends of the tubes into the grooves in the surface of the tube-sheets, I am enabled to make the joints more tight and rm and at less cost than with flanges riveted, and without occupying so much room as when flanges are employed, from which it follows that the tubes can be placed much nearer.

What I claim as my invention, and desire to secure by Letters Patent in the construetion of tubular steam-boilers, is-

In combination with beads or their equivalents on the tubes, grooving the surface of the tube-sheets around or part-ly around the tubeholes to receive the metal of the tube when riveted, substantially as described, by means of which I ain enabled more effeetually to secure tight and strong joints than by any other known method, as set forth.

JAMES MURPHY. NVitiiesses: f

L. N. GLovER, ANDREW DE LACY. 

